Successfully completing the indicated mission to unlock the corresponding girlfriend, which you can then kiss for a health bonus:

Beatrice: "That Bitch" mission in Chapter 1.

Lola: "The Tenements" mission in Chapter 3.

Mandy: "Discretion Assured" mission in Chapter 4.

Pinky: "Carnival Date" mission in Chapter 2.

Zoe: "Smash It Up" mission in Chapter 5.

Fighting moves

Collect the hidden transistors and give them to the hobo. With each transistor, he will teach you a new move. The moves he teaches you in order are:

Uppercut: Hold X.

Leg Sweep: Press X, then hold X.

Side Kick: Press X(2), then hold X.

Five Punch Combo: Press X(5).

Roundhouse Kick: Press X(3), then hold X.

Overhead Punch: Press X(4), then hold X.

Transistor locations

Look on the autoshop roof.

During the "Help Gary" mission, make your way to the boiler room. It should be on the table next to the fire extinguisher.

Behind the Mexican restaurant next to the bike shop in Bullworth town.

Found in the fourth photography class on the Bullworth dam.

Look on the table on the right side of the door to the upstairs in the "Nerd Challenge".

Found on the ground just before you enter "The Tenements" building.

Free arcade games

Get the high score in "Consumo", "Monkey Fling", "Nut Shots", and finish in first place in all races in "Future Street Race 2165" and "Future Street Race 3D".

Free soda

Drink 220 sodas to get free sodas from the soda machines.

Use the following trick to get free sodas from soda machines when you have less than a dollar. Go up to any soda machine and repeatedly press Y until a soda drops down. You can repeat this as many times as needed.

Invincibility in dodgeball

While playing dodgeball, press LT to display the help screen immediately before an opponent has the ball. While the help screen is displayed, you will not be knocked out if you get hit. The ball will bounce off your player, allowing you to pick it up and go on the offensive.

Easy money

Go to the basketball court anytime after 4:00 p.m. to play the Penalty Shot mini-game. Bet the maximum of $20.00. Go up to the line, then press Circle to jump. Press A to throw while in mid-jump for easy knockdowns.

To make a lot of money quickly, save the game then go to the midget boxing arena at the carnival and make the largest bet possible. If you lose, load your game and repeat until you win.

Easy tickets

Go to the carnival, then go to the "Splish Splash" game. It is fast, easy, only costs $1, and results in three tickets each time. Additionally, go to the carnival, then go to the "Hammer" game. Repeatedly tap A to get three tickets every time, if done correctly.

Easy Faculty Taunts

Go to the Principle's office and taunt the secretary. When she starts to chase you, just run around the desk and continue taunting her (while locked on with LB) for as long as desired. If she grabs you, just tap Y(10), or if she is not already irritated, you can just keep apologizing, which also helps your stats. This works for almost all staff -- just run and taunt.

Easy yearbook photos

To get a lot of photos in the Yearbook, go to either dormitory, pull the fire alarm, stand by and press Up, then start snapping them as they run by.

Easy Lola's Race

Before you start the "Lola's Race" mission, get a motorized bike. Drive it to where you start the mission. You will be able to race with the motorized scooter while everyone else in the race has a normal bike. You will go much faster, but the handling is worse.

Fighting multiple opponents

When fighting more than one opponent, sometimes you will get hit from behind. To prevent this, push over as many opponents as you can until there is only one person standing. Beat on him for a short time, then push him over when somebody else gets up. Beat on the person who got up and push them down when others get up. Try to keep as many on the ground as possible while only handling one or two enemies at a time.

Get some itching powder. When you get into a fight, if you need help set your weapon as the itching powder and throw it at one of the people you are fighting. They will start to itch. While they are itching, beat them up. The itching powder should last long enough for you to beat them or at least get their health in the red zone.

Saving others from beatings

To save someone from a beating, grab the attacker(s) by pressing Y and throw them far away from the victim -- so they will focus on you, and you will not accidentally hit the victim.

Destroying all pumpkins and tombstones

After starting the "Halloween" mission, you can get a bonus for finding and smashing all the pumpkins and tombstones around campus. If you do not find all of them, do not worry. In the next (and last) mission of the chapter, where you go into the basement of the school with Gary, you will get to the boiler room. Inside will be all of the pumpkins you missed in the "Halloween" mission. Kick all of them for an unlockable. Later in the game when you unlock the "Preppie" part of town, go to the asylum. Next to it will be a warehouse, and inside are all of the tombstones you missed.

Faster pointer movement in Biology class

Use the Left Analog-stick and Right Analog-stick together to make the pointer move faster, thus giving you more time to complete the assignment.

English class words

The following is a list of the letters you are given in each English class and the minimum number of words required within the time limit to pass the class:

English Class 1: The letters are "ELMOLW" and you need 7 words to pass the class. Here are words that can be created from those letters: Ell, Elm, Low, Mel, Mew, Mol, Mow, Ole, Owe, Owl, Lowe, Meow, Mewl, Mole, Moll, Well, Mellow.

It is possible to finish the game without 100% in all missions. However, if you watch the end credits you will see that Chapter 6, "Endless Summer", has been unlocked, which allows you can do any missions that you may have missed.

Getting in the girls dorm unseen

Unlock the Black Ninja costume by filling the yearbook. Then, go to a wardrobe and change into the Black Ninja costume. Go directly to the girls dorm and walk in. If you look at the map, you will notice that the yellow bar is at 0%. The staff will not see you unless you raise the yellow bar, but the students will.

Girlfriends fight

Kiss one girlfriend then walk slowly until you find another girl you can kiss. You must walk slowly so that the girl you just kissed will follow you. When you kiss the next girl, the two girls will start fighting.

Kissable cheeleaders

All the kissable girls are cheerleaders, except Beatrice (nerd girl), Lola (greaser girl), Zoe (townie girl), and the fat girl. You can see the girls as cheerleaders during the Gym class hour at football camp.

Kissing Kirby

After Chapter 5, you can kiss Kirby the jock.

Kissing Vince

After Chapter 3, you can kiss Vince the greaser.

Trent romance

Get flowers from the girls dorm, then talk to Trent. If you talk to him twice, it will bring up the option to give him flowers. When you do so, the lips will appear and you can kiss him. Note: You must complete the first chapter in order to do this.

Go directly to lesson

If you do not want to walk or run to a lesson, just throw something at the Prefects to get yourself busted. They will then take you directly to the lesson.

Shirts

After defeating a Boss (such as Russell), you can find their shirts in your room.

Recommended costume

Go to a wardrobe where you can change. Put on the school uniform then go to "Head". Switch it from nothing to the mascot head. By doing this you will get good compliments on clothing, and making out time with girls is reduced, which gives you extra time and the health bonus.

See the "Bitch" vomit in "That Bitch" mission

Hide in the trash can behind you after you place the stink bomb in "her" locker. When she does not see you, she will vomit and continue to do so as you make your escape. If she catches you before you hide, she will run away screaming.

Defeating Rustle

Throw a few fire crackers at him, then get up close and start punching him. Do this until he is defeated.

Easy "Kickin' The Balls" achievement

To easily get the "Kickin' The Balls" achievement, use the soccer ball located outside and to the right of the Boys Dorm. Go to the right-hand side of the dorm, and repeatedly kick the ball against the wall. If you wait until after 11 p.m. to do this, you can unlock the "Kickin' The Balls" and "After Hours" achievements in just two nights.

Easy "Soda 'Licious" achievement

Once you unlock the city, go to Yum Yum market, and scroll over the soda. Repeatedly tap A(100) to get the "Soda 'Licious" achievement.

Achievements

Accomplish the indicated achievement to get the corresponding number of Gamerscore points: